What sound might indicate that a vehicle's brake pads are worn?

The presence of squeaking or grinding noises during braking is a significant indicator that a vehicle's brake pads may be worn. When brake pads wear down to a certain level, they can produce a squeaking sound as the wear indicators, which are designed to alert the driver of diminished pad thickness, come into contact with the brake rotor. If the pads are severely worn, they can lead to grinding noises, which often signal that the pads have worn down completely and the metal backing is making contact with the rotor. This condition not only compromises braking efficiency but also can cause damage to the brake rotors themselves, resulting in costly repairs if not addressed promptly.

Other sounds, such as humming, rattling, or even silence, do not specifically indicate brake pad wear. Humming noises may relate to other components, while rattling sounds might suggest loose parts that aren't directly linked to brake pad wear. Silence might imply that the brakes are functioning normally, but it does not provide any information about the condition of the brake pads themselves. Thus, squeaking or grinding sounds during braking serve as clear warnings to drivers that maintenance could be necessary.